Grinding machine



July 19, 1938. (1 WELLS 2,124,093

GRINDINGMACHINE. Y

Filed July 5, 1955 5 Sheets-Sheet 1 IN VENTOR,

ATTORNEY.

July 19, was. Q W LL 2,124,093

GRINDING MACHINE Filed July 5, 1955 5 Sheets-Sheet 2 INVENTOI;

i l I 97 61244; 40?

ATTORNEY.

y 19, 1938. F. o. wEL'Ls' 2,124,093

FRINDING MACHINE I INVENTOR,

ATTORNEY.

July 19, 19 38. V Q. W LL 2,124,093

GRINDING MACHINE Filed July 5, 1935 5 Sheets-Sheet 4 INVENTOR, 1 10M dfil ATTORNEY.

July 19,1938. F. o. WELLS 2,124,093

' GRINDING MACHINE Filed July 5, 1955 5 Sheets-Sheet S 1N VEN TOR,

my j 0. Welel's;

I J .93 BY ATTORNEY.

Patented Julyl9, 1938 UNITED STAT S PAT- Eur oFFic-E.

, GRINDING MACHINE I v Frank 0. Wells, Greenfield, Mass, assignor to ICarroll E. Adams, Pawtucket, R. I.

Application July 5, 1935, Serial No. 29340 8 Claims.

My invention relates to improvements in grind? ing machines, andmoreparticularly to that type of grinding machine intended for use in thesharpening of drills and taps.

An object of my invention is to provide a sharpening machine, combinedin a single structure for sharpening drills and taps, that issemiautomatic in its action, which will quickly and efiiciently sharpena drill or tap, and which may be set to accurately grind the cuttingedges and v the lip clearances of a drill point to the proper angles,and the land faces and flutes of a tap to the proper angles of clearanceand hook.

A further object of my invention is to provide means on my machine forgrinding corners at the intersections of the faces of the drill pointand the sides of the flutes. At the present time, it is customary togrind drills with a sharp corner or edge at these intersections. It hasbeen found by exhaustive experiments that the life and cf.- ficiency ofa drill may be multipled many times by rounding or removing thesecorners or intersections and therefore materially save the cost ofpurchasing a new drill.

These and other objects and advantages of my invention will appear inthe accompanying drawings, the specification, and the appended claims.

Broadly, my invention comprises a base member, a motor mounted on thebase member, aplurality of grinding wheels secured to and actuated bythe motor, chuck and quill means for holding a drill or tap to beground, adjustable bearing members pivotally secured to the base memberin'which the quill is slidably secured,.cam means on the quill forcontrolling the movements of the drill or tap against the grindingwheels, means for locating a drill or tap in the quill in properrelation to the cams, and means for dressing the grinding Wheels for thepurpose of maintaining their faces in a true and sharp condition.

A preferred embodiment of my invention is illustrated in theaccompanying drawings, in

which:

Fig. 1 is a side elevational view of the complete grinding machine,showing the drill locator, motor, grinding wheels, the two pivotedposts, the

' pivoted housing with quill assembled therein in the right hand postposition for grinding the point of a drill, and the housing in the lefthand post ready to receive the quill for the purpose of grinding roundedcorners of a drill on its edges, or removing them by grinding on achamfer.

Fig. 2 is an end elevational View of Fig. 1 of the grinding machineillustrating the method of pivoti ng theposts for the purpose of feedingthe work to the grinding wheels.

Fig. 3 is a longitudinal sectional view of a drill and chuck assembledin the quill.

Fig. 4 is a cross sectionalvie'w on the line 4-4 of Fig. 3. v

Fig. 5 is a cross sectional view-on the line 5-5 of Fig. 3 illustratingthe cam for feeding the drill point across the face of the grindingwheel.

Fig. 6 is a side elevational view of the drill point locator with thequill assembled therein.

Fig. '7 is a plan view of the pivoted housing in which the quill issupported while the drill point is being sharpened.

Fig. 8 is a. detailed elevational view of the housing and quill shown inFig. 7,.in the same position as that shown in Fig. 1.

Fig. 9 is a side elevational View of'the housing shown in Fig. 7,looking in the direction of the view on the line as that shown in Fig.1.

Figs. 13 and 13 'are plan views of the point of a drill which has beensharpened on this machine. I

Figs. 14' and 14 are side elevational views of the point of the drillshown in Fig. 13 and Fig. 13A. 1

Fig. 15 is a partial side elevational view corresponding to Fig. 1showing the pivoted-housing in the right hand post with quill assembledtherein and adjusted in position for grinding a tap and the tap restsecured in the left hand post by means of which the flutes of the tapare ground.

Fig. 16 is a side elevational view of the tap rest shown in Fig. 15.

. Fig. 17 is a diagrammatic transverse sectional view of a tapillustrating the results obtained by the use of the grinding machine.

Fig. 18 is an elevational view of the adjustable dressing tool used todress the grinding wheel to the proper shape for rounding the corners ofa drill point.

Fig. 19 is a. plan view of the dressing tool shown in Fig. 18, and

' Fig. 20 is plan View of the dressing tool used for facing the grindingwheel ce-operating with motor 2 to which are secured in the usual mannerthe grinding wheels 3 and 4, the drill point cator 5, the details ofwhich are shown in Fig-:3

in section, and the post 5 which supports the' wheel guard A shaft 3 issecured in the base member I, and the posts 3 and II are pivotallysecured on this shaft by means of the bearings The extent of swing ofthe posts 8 and II on the shaft 8 is controlled by the adjusting screwsl2 and. i3. The post i3 is formed with the socket l4, in which theshanks of the drill housing turn; also the tap rest, or, the wheeldresser, may be secured by the wing set screw l5.

In describing the drawings, the methods and attachments used in theprocess of sharpening the point of a drill'will be first described, thenthe methods and attachments used in the process of sharpening a tap, andfinally the devices used for dressing the grinding wheels.

Figs. 3, 4, 5, and 6 illustrate the means for holdinga drill in thequill and for locating the lips of the drill in proper relation to thecams on the quill and quill housing. The drill i5 is slipped into thespring chuck I! having spring fingers and held lightly in place by aslight turn on the tightening knob II. The chuck I1 is formed with thetapered and split end portion I3, which engages the tapered surface 28of the quill 2|, and the tapered and split end portion 22 which isengaged by the tapered surface 23 of the threaded tightening shaft 24 towhich the knob I3 is secured. The chuck I1 is formed with thealternately spaced slots 25 and 25, and the ends of the chuck. II arealso formed with slots 21 and 28. This construction permits the fingersof the chuck to be gripped and compressed at each end simultaneously,which results in a firm, double grip on the shank of the drill. Thetightening shaft 24 is adjustable in the quill 2| by means of thethreads 29, and, by unplug the knob l8, the spring ends of the chuck arecompressed or expanded to grip or to free the drill. The quill 2| hassecured thereto, by

means of the 'set screw at the end opposite the drill point, the cammember 30, formed with oppositely located lobes or cars 3| and havingsecured in the body 32 the cam or locating pin 33.

While the drill is still lightly held in the chuck, the quill 2| isplaced in the bearing portion 24 of the locator 5, and is revolved untilthe lips of the drill point are engaged in the locator button 35, (seeFig. 6), which is retained in-the bearing portion 35 of the locator 5with the set screw 35. With the drill point held by the button 35, thequill is pushed forward until the cam 38 impinges against the pin 31,then revolved until pin 33 is brought into engagement with the pin 31.The knob I8 is then turned until the drill I5 is tightly grippe in thechuck IT. This procedure locates the drill in the quill with the of thedrill point in the proper relation to cam 30. I

After the drill has been properly set in the quill, the'quill 2|, withthe drill l5 gripped therein, is removed from the locator 5 and placedin the pivoted bearing or housing 4||, illustrated in! Figs. '7, 8, 9,and 10. The bearing is pivotally secured on the post 5 by means of thearm 4|, pivot bearing 42, and pivot shaft 43. The

The base member I has mounted thereon the axis or center line of thepivot shaft 43 inter.-

' sects with the axis or center line of the radius to which the cuttingedges of the drill point will be ground. The adjusting screw 44,impinging against the lug 45 formedon the 'post 3, may be set to bringthe axis of the housing 48 to any desired. angle relative to the face ofthe grinding wheel 4. For grinding the cutting edges of the drillpoints, this angle is usually 59 degrees, but may be varied if desired.The adjusting screw 44 has a threaded connection in the arm 4| of thequill housing 48, and as the screw 44 is threaded into the arm 4|, itimpinges against the lug 45 and forces this arm and quill bearing 45 toswing around the pivot shaft", as illustrated by the arrow 45 in Fig.10. The post 3 is also formed with the extending arm 41, to which issecured the cam-enga ing rod 43 by means of the clamp 43, stud 53, andscrew 43. The stop lug 5|, formed on the pivot bearing 42, co-operateswith the adjusting screw 44 to hold the bearing 45 with its axisparallel to the face of the grinding wheel 4 when the wheel is beingdressed. In this position, the stop lug 5| is in contact with the post3, and prevents further movement of the bearing 43. This operation willbe more fully explained later. The cam munber 52 is secured to thebearing 43 by the set screw 53, and' is properly aligned with thebearing 48 and the drill |5 by means of the indicator marks DD", on camand bearing as a reference mark 52' for positioning a drill, see Fig. 9.The cam member 52 is formed with the cam face 54, on which the pin 33 ofthe double cam 35 rides. In operation, the quill 2| is pushed into thebearing 43 until the pin 33 engages the cam face 54, the quill 2| isthen revolved in a clockwise direction by turning the knob l3, and thecombined movements of the drill point I5 caused by.the action of thearms 3| of cam 38 against the rod 48, and, the pin 33 against the cam 52will cause the drill point l5 to be ground with the correct angle ofcutting lips and the jcorrect eccentric relief or lip clearance.

and 20 on the top face of the clamp 49, shown.

in Fig. 7, assist in the proper location of the rod 48. 1

- The housing 45, carrying the quill 2i and drill I5, is fed toward thegrinding wheel 4 by the adjusting screw l2, shown in Figs. 1 and 2, andas the grinding wheel is worn down, the loss in diameter is alsocompensatedby swinging the post 9 inward by the adjusting screw I2.

After the drill point l5 has been ground to the properangle and reliefagainst the grinding wheel 4, the quill 2| is removed from the bearing43 and inserted in. the bearing 55, illustrated in Figs. 11

, and 12. The bearing member 55 is formed with the standard 55' andslide 51-. The slide portion 51 is slidably secured in the slide bearing58, and

its position relative to the slide bearing 58 is regulated by theadjusting screw 58. Once properly set, the slide 51 is secured by theset screw 58. The slide bearing 58 is formed with the shank portion 6|,which is removably-secured in the socket |4 formed in the pan II, by theset screw 55. The angle of the axis of the bearing 55 with the face ofthe wheel 9 may be adjusted by turning the shank ti in the socket is andadjusting the slide 57 with the screw 59. The cam 62 is secured to thebearing 55 by means of the set screw $3. The purpose of the cam is tofeed the drill point toward the grinding wheel, in order to form arelieved rounded, or chamfered corner on the drill point it. The cam 62is formed with the cam face 66, on which the pin 33 rides. The quill 28is inserted in the bearing 55, until the pin 33 is engaged against the.cam face 64, then the quill fl is revolved by turning the knoblt; Thegrinding wheel 3 is formed with the concaveshaped face 55, and as thedrill point it is fed forward and backward against and away from theface 55, a relieved rounded corner is formed at the intersection of thefaces of the drill point and the sides of the flutes. If the wheel 3 hasa flat face, a chamfered corner is formed, as indicated at it, in Figs.13 and 14 The result of the operations above described is to sharpen thedrill it with both cutting edges 66 exactly alike as to length andhaving the same angle with the axis of the drill, as indicated at 67 and68 in Fig. 14. The angle of lip clearance, or contour of the reliefsurfaces 59 and Ill back of the cutting edges is the same for bothcutting edges. The drill has been shaped with the rounded comers ii and12 or, chamfered corners ltflld", both exactly alike. Thus the sharpeneddrill point has been shaped to be correct according to thebest practicein every respect, and in addition, the rounded corners H and F2 or,chamfered corners i6", it increase the emciency and life of the drillmany times.

If it is desired to thin the web of the drill point 36, as indicated atE3 and 16 in Fig. 13, this may be accomplished by the use of the taprest, indicated in Figs. 15 and 16 in cooperation with the grindingwheel 3'.

Figs. 15, 16, and 17 showthe manner in which at by bringing theindicator marks T T- into registration on cam and housing, shown in Fig.15. The housing id is set at the proper angle with the grinding wheel 6corresponding to the taper of the tap end Tl by the adjusting screw 6%,the quill 2i inserted in the housing d0 until the pin 33' engages theface til of the cam '89, and the quill 2i turned in a clockwisedirection by the knob I8.

The tap is moved in and out across the face of the wheel ti by the camface 80, thus causing a correct relief, indicated at 89 in Fig. 1'7, tobe ground on the tapered faces of the lands id. The cam face til is cutwith a plurality of high points 32 equal in number to the number oflands on the tap to be ground. The housing 40 is fed toward the grindingwheel d'by the feed screw it, in the same manner'as that employedfordrills.

' When sharpening taps, the flutes 83 should be are-ground to provideplenty of chip room and the correct hook or rake for free cutting. Forthis operation, the tap it is held on the V-shaped tap rest i1 3, andfed to the narrow formed grinding wheel 3' by the feed screw it. The taprest dd is formed with the round shank 85, which is adjustably securedin "the secket M of the post it by the set' screw id. The angle of thetap rest, relative to the wheel 3', may be adjusted by turning the shank85 in the socket M to provide the correct hook.

Figs. 18 and 19 illustrate the dressing device used for dressing theformed wheel which grinds the roundedcorners on the drill point. Asimilar device is used for dressing the formed wheel used in grindingthe flutes of taps. The diamond-- pointed dressing tool 85 is secured inthe swinging support member d'i which is formed with the handle 86 andshaft 8d. The shaft portion 89 is .pivotally supported in the bearingportion 90 of ber 92 and the pivot-supporting member M,

respectively.

The straight faces of the wheels 3 and 6 are dressed with thetool'illustrated in Fig. 20. The diamond pointed dressing tool 95 issecured in the-reduced end. portion 91 of the shaft 98. The shaft 98 isformed with the same diameter as the quill 2i, and has formed at the endopposite the diamond point 96 the knurled knob. 99. In operation, theshaft 98 is substituted in the housing Iii for the quill 2 I. Thehousing 40 is swung around on its pivot 43 in the bearing 42 by theadjusting s'crew at until the curved stop lug 5i engages the post 9. Inthis position, the axis forth across the face of the wheel a. The facework which they are designed to accomplish.

It will be observed, with reference to Figs. 13 and 14 that the cornerportion, indicated at it, is chamfered, instead of being formed curvingor rounded, as in Figs. 13 and i4, at El and i2.

What I claim is:

1. In a grinding machine, a. grinding element, means for operating thesame, a. pivotally supported post, a pivotally supported .housing memberon said post, means for rotatably supporting a tool to be ground. as adrill, in the housing member, means when the tool is, rotated in thehousing member for moving the tool across the grinding element and forsimultaneously of wheel 3 may be dressed straight in the same formingthe relief on the tool point, said means tion with a grinding element, amovably mounted post, a tool-receiving housing pivotally mounted on saidpost, an adjustable arm on the post, a tool chuck rotatably mounted inthe housing, a cam on the chuck engaging the arm for, moving the tool tobe ground across the face of the grinding element for imparting a reliefsurface. to the tool, a second cam on the housing and a member on saidfirst cam engaging said second cam for controlling longitudinal movementof said chuck.

3. In combination in a grinding machine, a base member, grindingelements on the base member, means for operating the grinding means, ashaft in said base member, posts pivotally supported on said shaft,members for supporting tools to be ground pivotally supported on saidposts, means for positioning the toolsupporting members in angularrelation to said grinding elements, means for moving the posts towardand away from the grinding elements, and cam' means for imparting arelief. for the cutting edges of the tools when the tools are rotated-inengagement with said grinding elements.

4. In a drill grinding machine, a grinding element having a concaveface, a post, a housing pivotally supported on saidpost, a tableslidably supported in said housing, means for adjustably positioningsaid table relative to the axis of said post, a bearing sleeve on saidtable, a quill for holding a drill slidably and rotatably supported insaid sleeve, a cam on said sleeve, a stud on said quill and inengagement with said cam for imparting longitudinal movementto saiddrill when said drill is. rotated, whereby the shoal-- ders of the drillpoint will be chamfered with a relief angle identical. with the reliefangle on the face of the drill point.

5. As a constituent mechanism of a machin holder operating a screw foractuating saidmeans. t

6. A drill sharpening mechanism comprising a grinding wheel, a supportmovably mounted adjacent thereto having a cylindrical bearing openingtherein, a separable drill holder having means unitary therewith forclamping the drill centrally therein in a flxed'position and having aforwardly extending cylindrical shank free of radial projectionsadjacent the forward end thereof and constructed and-arranged to fitsaid bearing and be entered thereinto from the rear side, cam elementson the holder adjacent the rear.en d thereof, a cam element on thesupport and a cam element adjacent thereto for cooper-. ,atingrespectively with said elements on the holder for controlling axial andswinging movements of the drill during the grinding operation.

7. A drill sharpening mechanism comprising a grinding wheel, a supportmovably mounted adjacent thereto having a cylindrical bearingopenholder, and'means at the rear of the holder for applying rotativemovement to the same.

8. A drill sharpening mechanism comprising a grinding wheel, a supportmovably mounted adjacent thereto having a cylindrical bearing openingtherein, a separable drill holder having means unitary therewith-forclamping the drill centrally therein in a fixed position and having a.forwardly extending cylindrical shank free of radial projectionsadjacent the forward end thereof and constructed and arranged to fitsaid bearing and be entered thereinto from the rear side, a cam elementprojecting in a transverse plane at the rear of the holder, acooperating element adjacent the support cooperating therewith,cooperating cam elements on the forward face of said first mentioned camelement and the rear face of the holder, and means at the rear of theholder for applying rotative movement to the same comprisinga wheelhandle effective to operate the drill clamping means. I FRANK O. WELLS.

